These bones are the lower ends of the femur. They only fuse with the main 'shaft' of the bone when the animal has stopped growing, so these are from young animals. The lower photos are from a large herbivore (cow/horse), the upper ones are less distinct but on the basis of size may be sheep.

Thank you John, with the information you provided ( much apreciated ) i got further informations

Horses, as we all know, have many special abilities. Among the less dramatic, but no less important, of these abilities is their ability to sleep standing up. Horses have a complex system called the passive stay apparatus that allows them to do this while using minimal muscular effort. One of the keys to this system is the ability to lock the kneecap (patella) in place, which keeps the stifle extended. The medial patellar ligament is connected to the patella with a flexible extension called the parapatellar fibrocartilage. This is the portion that actually ‘locks’ onto the prominent medial trochlear ridge of the femur. So we have a parapatellar fibrocartilage here T